Sex effect on growth performance and marker-aided sex discrimination of seedlings of Populus deltoides

Sex has a significant effect on various traits among dioecious plants.In this analysis of the sex effect on the radial growth and wood density of numerous 20-yearold trees of Populus deltoides growing in a common garden,male trees performed better than the females in radial growth,but sex did not significantly affect wood density.Growth rate and wood density were weakly negatively correlated.Sex selection is also critical for controlling seed-hair pollution from P.deltoides plantations.However,because the juvenile period of P.deltoides lasts for years,a reliable technique to determine the sex of juveniles has been needed.Here we developed a marker-aided technique to discriminate the sexes of P.deltoides seedlings.This study provides essential information on target traits and a highly desirable genetic toolkit for accelerate breeding programs for this important tree species.

Adult Sex Discrimination Using Metric Measurements of Hand Digital Radiographs in Egyptian Population

Objective: The aim of the present study is to discriminate functions for sex determination in a subjected sample of the Egyptian population using the morphology of metacarpals and phalanges for gender comparison. Furthermore, the measurements discussed in this study will aid in predicting the differentiation independently and guaranteeing sex determination in the subjected population individually. Methods: Forty measurements were taken from the right metacarpals and phalangeal bones of 100 subjects, whose ages ranged from 19 to 60. Moreover, the measurements of nine metacarpals and four phalangeal bones were used for sex discrimination in each sample population. Results: Males had significantly greater mean values (P < 0.05) for the lengths of the metacarpals and the proximal phalangeal bones of all right-hand fingers than females. The cut-off value and the accuracy percentage for precise sex classification of males and females using individual and grouped bones showed that a value higher than the marking point classified an individual as male and that a lower value suggested female. Besides, the multiple stepwise discriminant functional analysis of the most predictable internal variables of the metacarpals revealed a cross-validated sex classification accuracy of 100%. In contrast, the most predictable internal variables of the phalanges showed a cross-validated sex classification accuracy of 93%. Conclusion: The results revealed a new forensic suggestion for the determination of sex based on the measurements of the metacarpals and the phalanges. Moreover, various discriminant equations were applied for the declaration of this conceivable recommendation.

Airline Sued for Sex Discrimination Over Viagra

世界最大的航空公司(American Airlines)将不得不“对簿公堂”,因为,该公司的男性雇员可以免费享用“伟哥”,而女性雇员却不能相应的birth control pills,pap smears(注:关于pap smears的释义请见本期的“难句相与析”栏目)or infertility treatment!一位女性雇员奋起控告该公司。

Stereotypes in Genders Construction

The observation of girls and boys study in college for many years elicits there is a key to construct students' gender which affect their study and job choosing after graduation. In order to make teaching more effective and efficient, understanding what constructs genders becomes necessary for designing the curriculum. Some literatures tell that gender stereotypes exist ineradicably in our society. The gender stereotypes construct children's gender through their parents, mass media and their peer groups.The stereotypes believe boys wear blue and girls wear pink; boys always choose astronaut, lawyer, dentist as their job and girls prefer to be a nurse or a teacher. Gender stereotypes occur some negative phenomenon such as sex discrimination, restriction on personality development, and inefficient cooperation between male and female in our society. Educators should show a correct direction to students in their gender construction. There are 4 teaching approaches introduced to educator in the essay to reduce the influence of gender stereotypes on students. They are"access and equity""valuing girls' and boys' skills and experiences""acknowledging differences among girls and boys", and"challenging and critically examining the social structures". Students can understand themselves objectively and clearly, shape their personality positively, and develop their interests appropriately through the approaches in education.

Sex recognition does not modulate aggression toward nest intruders in a paper wasp

During social interactions,the behavior of an individual often depends on the sex of its social partner.Many animal societies have males and females that play very different behavioral roles,although they coexist and interact non-sexually.At specific phases of the colony cycle,social wasp females and males are contemporaries within a nest,they often interact,although mating occurs mostly off the nest,therefore providing an opportunity to test sex discrimination in contexts other than classical sexual ones.We performed a lure presentation experiment to test if Mischocyttarus metathoracicus discriminate between conspecifics of the 2 sexes during on-nest social interactions.Female wasps discriminated conspecific sex during experimentally simulated nest intrusions.Visual and chemical cues may account for this sex discrimination.Despite sex discrimination(evidenced by differential inspective behavior from the nest females toward the female and the male lures),female wasps were as aggressive toward lures of both sexes.In the female-dominated hymenopteran societies,males are often subordinate and not aggressive on nest,resulting in females directing less aggression to them compared to other females.Instead,M.metathoracicus males and females are both aggressive toward nestmates,so they might be perceived as similar threat during on-nest social interactions.